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chris, Ford Mechanic
Category: Ford
Satisfied Customers: 3521
Experience:  ASE Master -Ford senior master-20 years experience
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My A/C blows cold while sitting still then goes warm while

Customer Question

My A/C blows cold while sitting still then goes warm while driving. This is shortly after having the system recharged, so I assume the 134A and what not is proper.

This is a 2003 Escape with 130k miles. Never had problem with A/C until now.
Submitted: 8 years ago.
Category: Ford
Expert:  chris replied 8 years ago.

Hi there


A a/c system usaly blows colder when driving then sitting still, so i do not think its a freon issue ,,, it sounds just like a car that is overheating , like it has a stuck open t-stat .


take it for a driver and look at your temp gauge ,,,does the temp gauge go to hot at the same time the a/c starts to blow warm ???


check the coolant reservoir ,, is there coolant in there ??


Who did the recharging on the a/c system ???did they do other work to the truck also ??? like to the cooling system


we can go back and forth on this page



chris and 4 other Ford Specialists are ready to help you
Customer: replied 8 years ago.
I have done all preventative maintenance, which included flushing the cooling system. To be honest, I had the 90k work done end of last summer which was about 110k...spend around 2k for all the work done....but right before winter hit was when I noticed this problem and decided not to worry about it until it got hot outside. They did flush the cooling system as well as check/recharge the A/C. I haven't noticed any overheating (per the temp gauge) but I'm about to run to the store and will double check...but I can almost guarantee this isn't an issue.

The mechanic is a good friend of mine who runs a very reputable shop ( I'm just wanting to avoid paying labor to replace a switch/relay or something that I could well do myself. I'm more than able to replace a thermostat if that turns out to be the issue.

The change from cool to hot and vice versa is very gradual, and the temp out of the vent even while sitting still in not as cold as I would expect. I'll check the coolant reservoir as you suggest.

Back in about 30 minutes - thank you. 3:00pm Central time.
Expert:  chris replied 8 years ago.

Take your time and get back to me when you can ,,, the only other thing is that if they over charged the system ,,then you will get the consern that you have ,, but tell me what happens after your test drive



Customer: replied 8 years ago.
Well, went for a drive and the temp is fine as well as the coolant level.

I bought a can of 134 with gauge - connected it to the low side, pierced the top, opened the valve all the way and the gauge was totally pegged. I mean like way beyond the highest point of the red.....the needle stopped only because it was at 6 oclock and couldn't go any further.

Would you say that means the system is overcharged?
Customer: replied 8 years ago.
Also - the clutch on the compressor constantly engages and disengages every 2-3 seconds while the A/C is on full blast with recirc.
Customer: replied 8 years ago.
When I connect the 134 can w/out opening the valve on it - the gauge is right in the top 2/3 of the green.
Customer: replied 8 years ago.
I have it in the driveway now and it's not blowing cold at all. I hear a hiss from behind the firewall, then the clutch engages and immediately disengages........thats a more accurate description of what the compressor is doing.
Expert:  chris replied 8 years ago.

Ok --if the a/c compressor is going on and off fast on high blower then this is a sign that the system is low on freon .. with a system that has the proper freon level , on high blower the compressor should stay on all most all the time and never go off


When I service an a/c system , I have to hook up a machine to the low side and high side service ports and doing this may make a leak in the system after I remove the machine ,, the service ports stick and the freon leaks out ,, or they just did not put the proper amount in the system ,,,


It does sounds like a charging issue and would bring it back to them and have them re service it and make sure the service ports are not leaking ,,


I just got your other post ----when I look at a a/c system ,,I am looking PSI on the machines gauge ,, like the low side should be at 30 psi and the high side at 211 pis ,,,,so the gauge that you are useing is not a real good way to diag an a/c system




Customer: replied 8 years ago.
Thanks Chris - I'm going to try and fill it up - if that doesn't work I'll take it to them.

Is there any danger in just hooking up the can, opening the valve and letting it sit for a while? The can says 5-15 minutes should empty the can.
Expert:  chris replied 8 years ago.

NO --there is no danger ,,, fill the system on the low side service port ,,with the truck on and a/c on ,,also on high blower ,, so it will take the freon easier


good luck


Thanks, Chris

Customer: replied 8 years ago.
Expert:  chris replied 8 years ago.

No problem ,


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